﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ch03_1
{
    class Class4
    {
        static void Main(string[] args)
        {
            //多分支的if语句
            Console.Write("请输入你的成绩：");
            double score = double.Parse(Console.ReadLine());

            if (score > 100 || score < 0)
            {
                Console.WriteLine("输入有误");
            }
            else if (score < 60)
            {
                Console.WriteLine("差");
            }
            else if (score < 70)
            {
                Console.WriteLine("中");
            }
            else if (score < 80)
            {
                Console.WriteLine("良");
            }
            else
            {
                Console.WriteLine("优");
            }
            
            

        }
    }
}
